Process of making dies



April 9, 1929. R M, AK N 1,708,715

PROCESS OF MAKING DIES Filed March 1927 I. EXTOR. Men/b H14 (flkim/ (fond-M 77 Patented 'Apr. 9, 192 9.

UNITED STATES means ROBERT M. AKIN, OF OSSINING, NEW YORK.

PROCESS OF MAKING DIES.

Application filed March 1, 1927. Serial No. 171,796.

This invention relates to processes of making dies, particularly such dies as are employed for drawing metals into wire or tubes. The object of my improvements is to provide 5 a simple, inexpensive and rapid method for producing dies of the character described.

While my improvements are particularly useful and applicable to the. production of dies for drawing very fine wire, said improvements are fully applicable to a wide variety of analogous results. Heretofore, the making of dies for drawing fine wire, some of which is but a few thousandths of an inch in diameter,

- has been an expensive and tedious operation and one requiring much skill and patience, as the drilling of holes of very small diameter in hard substances is slow and difiicult. By my improvements, greatly increased speed of production is attained together with accuracy of result. K I

In the drawing accompanying this specification my improved process is illustrated in a series of more or less diagrammatic figures, wherein Figure 1 is-a plan yiew of a portion of a mandrel about which my improved die is formed. Fig. 2 shows the die, in section, on

said mandrel. 'Fig. 3 is a lengthwise section of the die enclosed in a convenient holding ring.

- While heretofore hard stones, such as diamonds, with holes drilled therethrough, have been the accepted and preferred material for small dies, metals naturally hard, or hardened by known methods have been used with success. But the naturally hard metals, such as, for instance, chromium, are exceedingly difiicult and expensive to work with tools. By my 'improved process of electric deposition, such metals may be employed and formed into dies with speed and economy.

The mandrel of Fig. 1 may-comprise a wire or rod 2, a portion 3 of which is shaped to conform to the inside profile of the desired die, the midportion 4.being necked down to a 15 diameter equal to that of the wire intended to be drawn thereby. Also, while the crosssection of portions 3 and 4 may usually be round, it is obvious that such cross-section may be polygonalor of other shape, so as to produce wire of an desired cross-section.

Having prepare themandrel 2, preferably formed of metal or some other convenient material coated with plumbago or the like, I deposit or build up thereon between shoulders 5, a coating of metal 6 suitable for use as a die. This deposition or. building up may be I done by some known means as electrically. Also the coating may be deposited to a thickness sufficient to give the necessary rigidity and strength for the purpose. '6 .Said die, thus produced, may be mounted in some convenient holder but preferably I electrically deposit thereon a shell of softer metal, suchas for instance, copper 7, or said shell may be applied by melting the holder metal and pouring it into a mold about the die.

, Previous to, or subsequent to the application of holder member 7, mandrel 2 is removed from the die, by breaking the mandrel at 4.

There is thereb produced a die, having a hole therethrougl of a desired character adapted for wire drawing or the like.

I claim: p e

1. That improvement in the process of forming a die including preparing a mandrel with a portion thereof shaped to conform to the cross section of the wire desired to be produced by said die, said mandrel increasin in size in opposite directions'from said shaped portion, depositing electrically on the dieshaped portion of said mandrel a coating of metal, breaking said mandrel. at said shaped portion and removing the two portions of said mandrel from within said coating of metal. 7

2. That improvement in the process of forming a die including preparing a mandrel with a portion thereof shaped to conform to .the cross section of the wire desired to be produced by said die, said mandrel increasing in size in opposite directions from said shaped portion, building up on the die-shaped portion of said man'drel a coating of metal adapted for use as a die, su'rroundin said dieshaped coating of metal with a she I of metal, breaking said mandrel at said shaped portion and removing said mandrel from within said coating of metal.

In witness whereof, I hereby aifix my signature this 28 day of February, 1927.

ROBERT AKIN. 

